Light-emitting device, method for manufacturing the same, and display panel

Abstract

The application discloses a light-emitting device, a manufacturing method thereof and a display panel. The manufacturing method of the light-emitting device comprises the following steps: providing a first device plate; applying a metal oxide mixed solution on the first device plate; performing first annealing treatment on the metal oxide mixed solution at a first preset temperature to form a first electron transport layer; performing second annealing treatment on the metal oxide mixed solution at a second preset temperature to form a second electron transport layer, the second electron transport layer being located on a side of the first electron transport layer away from the first device plate, wherein the second preset temperature is greater than the first preset temperature; and forming a second device plate on a side of the second electron transport layer away from the first electron transport layer.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a light-emitting device and its manufacturing method, and a display panel. Background Technology

[0002] Quantum dots are nanocrystalline particles with radii smaller than or close to the Bohr exciton radius, typically ranging from 1 to 10 nanometers in size. They exhibit quantum confinement effects and can emit fluorescence when excited. Furthermore, quantum dots possess unique luminescence properties, such as broad excitation peaks, narrow emission peaks, and tunable emission spectra, making them promising for applications in optoelectronics. Quantum dot light-emitting diodes (QLEDs) are devices that use colloidal quantum dots as the light-emitting layer. This layer is introduced between different conductive materials to produce light of the desired wavelength. They offer advantages such as high color gamut, self-emission, low start-up voltage, and fast response speed.

[0003] Quantum dots can be used to adjust the band gap by modifying the size and composition of nanoparticles to obtain different red, blue, and green light emission properties.

[0004] In QLED devices, the commonly used electron transport layer is made of metal oxide nanoparticles with high mobility and their doped materials; the commonly used cathode materials are Ag, Al and their doped materials or composite layers.

[0005] However, current printed display device functional layers suffer from several problems: the work function of commonly used cathode materials differs significantly from the conduction band energy levels of quantum dots, creating a large potential barrier that hinders electron injection, leading to charge accumulation and reduced device efficiency and lifetime. Existing solutions typically involve fabricating multiple layers of differently doped metal oxides to form a stepped electron transport layer, thereby reducing the injection barrier and improving device performance. However, in printed display devices, conventional methods require multiple metal oxide printing processes, increasing the electron transport layer step, leading to higher production costs and lower product yield.

[0006] Therefore, it is necessary to propose a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0007] This application provides a light-emitting device and its manufacturing method, as well as a display panel, to solve the problem of cumbersome manufacturing steps for the electron transport layer in a light-emitting device.

[0008] This application provides a method for manufacturing a light-emitting device, including the following steps:

[0009] Provide the first component board;

[0010] A metal oxide mixture is coated onto the first device board;

[0011] The metal oxide mixture is subjected to a first annealing treatment at a first preset temperature to form a first electron transport layer;

[0012] At a second preset temperature, the metal oxide mixture is subjected to a second annealing treatment to form a second electron transport layer. The second electron transport layer is located on the side of the first electron transport layer away from the first device board. The second preset temperature is greater than the first preset temperature.

[0013] A second device board is formed on the side of the second electron transport layer that is away from the first electron transport layer.

[0014] In the method for fabricating a light-emitting device provided in this application embodiment, before the step of coating the first device plate with a metal oxide mixture, the method further includes:

[0015] A doped metal oxide is formed by doping a first metal oxide with a metallic element, wherein the metallic element includes at least one of magnesium and aluminum, and the molar percentage of the metallic element to the first metal oxide is between 5% and 20%.

[0016] A ligand is added to a second metal oxide to form a coordination metal compound. The ligand is selected from thiols, alkanolamines, and polyhydroxy ethers. When the ligand is selected from thiols or alkanolamines, the molar percentage of the ligand to the second metal oxide is between 0.1% and 10%. When the ligand is selected from polyhydroxy ethers, the molar percentage of the ligand to the second metal oxide is between 10% and 50%.

[0017] The doped metal oxide and the coordinated metal compound are dissolved in alcohol and / or ether solvents to form the metal oxide mixture.

[0018] In the method for fabricating a light-emitting device provided in the embodiments of this application, before the step of adding a ligand to the second metal oxide to form a coordination metal compound, the method further includes:

[0019] The second metal oxide is doped with ions selected from at least one of tin, selenium, or sulfur. When the ion is selected from cationic tin, the molar percentage of the ion to the second metal oxide is between 10% and 30%. When the ion is selected from anionic selenium or sulfur, the molar percentage of the ion to the second metal oxide is between 1% and 15%.

[0020] In the method for fabricating a light-emitting device provided in this application embodiment, before the step of coating the first device plate with a metal oxide mixture, the method further includes:

[0021] A doped coordination metal compound is formed by doping a first metal oxide with a metallic element and adding a ligand to the first metal oxide. The metallic element includes at least one of magnesium and aluminum. The molar percentage of the metallic element to the first metal oxide is between 5% and 20%. The ligand is selected from thiols, alkanolamines, and polyhydroxy ethers. When the ligand is selected from thiols or alkanolamines, the molar percentage of the ligand to the first metal oxide is between 0.1% and 10%. When the ligand is selected from polyhydroxy ethers, the molar percentage of the ligand to the first metal oxide is between 10% and 50%.

[0022] Provide a second metal oxide;

[0023] The doped coordination metal compound and the second metal oxide are dissolved in alcohol and / or ether solvents to form the metal oxide mixture.

[0024] In the method for fabricating a light-emitting device provided in the embodiments of this application, after the step of providing the second metal oxide, the method further includes:

[0025] The second metal oxide is doped with ions to form an ion-doped metal oxide, wherein the ions are selected from at least one of tin, selenium, or sulfur, and when the ions are selected from cationic tin, the molar percentage of the ions to the second metal oxide is between 10% and 30%, and when the ions are selected from anionic selenium or sulfur, the molar percentage of the ions to the second metal oxide is between 1% and 15%.

[0026] In the method for fabricating a light-emitting device provided in the embodiments of this application, the first metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO, and the second metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO.

[0027] In the method for manufacturing a light-emitting device provided in the embodiments of this application, the first preset temperature is between 40 degrees Celsius and 70 degrees Celsius, and the second preset temperature is between 75 degrees Celsius and 130 degrees Celsius.

[0028] In the fabrication method of the light-emitting device provided in the embodiments of this application, the first device plate is a quantum dot light-emitting layer, and the second device plate is a cathode; or,

[0029] The first device board is a cathode, and the second device board is a quantum dot light-emitting layer.

[0030] This application also provides a light-emitting device, which is manufactured by the above-described method for manufacturing light-emitting devices.

[0031] This application embodiment also provides a display panel, the display panel including an array substrate and the above-mentioned light-emitting device, the light-emitting device being disposed on the array substrate.

[0032] This application provides a light-emitting device and its manufacturing method, as well as a display panel. In the manufacturing method of the light-emitting device provided in this application, a multi-stage annealing process is used to form an electron transport layer, which solves the problem of cumbersome manufacturing steps for the electron transport layer in the light-emitting device.

[0033] To make the above content of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the light-emitting device provided in the embodiments of this application;

[0035] Figure 2 This is a schematic diagram of the structure of another light-emitting device provided in an embodiment of this application;

[0036] Figure 3 A flowchart illustrating the steps of a method for fabricating a light-emitting device according to an embodiment of this application;

[0037] Figures 4 to 9 A schematic diagram illustrating a method for fabricating a light-emitting device according to an embodiment of this application;

[0038] Figure 10 This is a schematic diagram of the structure of the display panel provided in an embodiment of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or working state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0040] This application provides a light-emitting device, a method for manufacturing the same, and a display panel, which will be described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0041] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this application. This application provides a light-emitting device 100, which includes a first device plate 101, a first electron transport layer 102, a second electron transport layer 103, and a second device plate 104. In this embodiment, the first device plate is a quantum dot light-emitting layer, and the second device plate 104 is a cathode.

[0042] Specifically, in some embodiments, the light-emitting device 100 may further include an anode 107, a hole injection layer 106, and a hole transport layer 105.

[0043] The anode 107, hole injection layer 106, and hole transport layer 105 are stacked sequentially. The first device board 101 has a first surface 101a and a second surface 101b that are disposed opposite to each other. The second surface 101b of the first device board 101 is attached to the hole transport layer 105. The first electron transport layer 102 is disposed on the first surface 101a. The second electron transport layer 103 is disposed on the side of the first electron transport layer 102 away from the first device board 101. The second device board 104 is disposed on the side of the second electron transport layer 103 away from the first device board 101. The first device board 101 is a quantum dot light-emitting layer, and the second device board 104 is a cathode.

[0044] In one embodiment, the anode 107 may be a transparent conductive oxide or a conductive polymer. The transparent conductive oxide may be indium tin oxide (ITO), fluorine-doped SnO2 conductive glass (SnO2:F), etc.

[0045] The hole injection layer 106 can be a conductive polymer, such as PEDOT:PSS; or it can be an n-type semiconductor with a high work function, such as HAT-CN, MoO3, WO3, V2O5, Rb2O, etc.

[0046] The hole transport layer 105 can be an organic hole transport layer, such as Poly-TPD, TFB, PVK, TCTA, CBP, NPB, NPD, etc.; or it can be an inorganic hole transport layer, such as NiO, Cu2O, CuSCN, etc.

[0047] The first device board 101 is a quantum dot light-emitting layer. The quantum dots can be II-VI group compound semiconductors, such as CdSe, ZnCdS, CdSeS, ZnCdSeS, CdSe / ZnS, CdSeS / ZnS, CdSe / CdS, CdSe / CdS / ZnS, ZnCdS / ZnS, CdS / ZnS, ZnCdSeS / ZnS, etc.; they can be III-V group compound semiconductors, such as InP, InP / ZnS, etc.; they can be I-III-VI group compound semiconductors, such as CuInS, AgInS, CuInS / ZnS, AnInS / ZnS, etc.; they can be IV group elemental semiconductors, such as Si, C, Graphene, etc.; they can be perovskite quantum dots, such as CsPbM3 (M = Cl, Br, I), etc.

[0048] The first electron transport layer 102 is disposed on the first surface 101a of the first device board 101. In some embodiments, the material of the first electron transport layer 102 may be a metal oxide doped with a metal element, wherein the metal oxide may be selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO, and the metal element may be selected from active metals such as magnesium or aluminum.

[0049] The second electron transport layer 103 is disposed on the side of the first electron transport layer 102 away from the first device plate 101. In some embodiments, the material of the second electron transport layer 103 may be a coordination metal compound, specifically, the coordination metal compound is formed by coordination of a long-chain ligand with a metal oxide. The long-chain ligand may be selected from thiols, alkanolamines, or polyhydroxy ether compounds, such as ethanolamine, butanethiol, or tetraethylene glycol, etc., and the metal oxide may be selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO, and InSnO.

[0050] In some embodiments, the material of the second electron transport layer 103 may also be an ion-doped coordination metal compound, wherein the ion-doped coordination metal compound is formed by ion-doped metal oxide and then coordination with a long-chain ligand. The long-chain ligand may be selected from thiols, alkanolamines, or polyhydroxy ether compounds, such as ethanolamine, butanethiol, or tetraethylene glycol; the metal oxide may be selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO, and InSnO; and the ion dopant may be selected from tin ions, selenium ions, or sulfide ions.

[0051] The second device plate 104 is disposed on the side of the second electron transport layer 103 away from the first electron transport layer 102. The second device plate 104 is a cathode, and the material of the second device plate 104 can be metal such as aluminum, magnesium, or silver.

[0052] Please see Figure 2 , Figure 2 This is a schematic diagram of another light-emitting device provided in an embodiment of this application. The light-emitting device 200 includes a first device board 201, a first electron transport layer 202, a second electron transport layer 203, and a second device board 204.

[0053] In some embodiments, the light-emitting device 200 further includes a hole transport layer 205, a hole injection layer 206, and an anode 207.

[0054] Specifically, the first device board 201 has a first surface 201a and a second surface 201b disposed opposite to each other. A first electron transport layer 202 is disposed on the first surface 201a, a second electron transport layer 203 is disposed on the side of the first electron transport layer 202 away from the first device board 201, and a second device board 204 is disposed on the side of the second electron transport layer 203 away from the first electron transport layer 202. A hole transport layer 205, a hole injection layer 206, and an anode 207 are sequentially stacked on the second device board 204. In this embodiment, the first device board 201 is a cathode, and the second device board 204 is a quantum dot light-emitting layer.

[0055] In some embodiments, the material of the first electron transport layer 202 is a doped coordination metal compound, wherein the doped coordination metal compound is formed by doping a metal oxide with a metal element and coordinating the doped metal oxide with a long-chain ligand. The metal element includes at least one of magnesium and aluminum, and the long-chain ligand can be selected from thiols, alkanolamines, or polyhydroxy ether compounds, such as ethanolamine, butanethiol, or tetraethylene glycol; the metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO, and InSnO.

[0056] The material of the second electron transport layer 203 can be a metal oxide or an ion-doped metal oxide. The metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO, and InSnO; the ion dopant can be selected from tin ions, selenium ions, or sulfide ions, etc.

[0057] The difference between the light-emitting device 200 in this embodiment and the light-emitting device 100 in the previous embodiment is that:

[0058] In the light-emitting device 100, the first device plate 101 is a quantum dot light-emitting layer, and the second device plate 104 is a cathode. In the light-emitting device 200, the first device plate 201 is a cathode, and the second device plate 204 is a quantum dot light-emitting layer. It should be understood that the light-emitting device 200 in this embodiment is an inverted structure of the light-emitting device 100 in the previous embodiment.

[0059] Next, the embodiments of this application will describe the fabrication method of the light-emitting device.

[0060] Please refer to Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The method for manufacturing the light-emitting device 100 includes the following steps:

[0061] Step B1: Provide a first device board 101, which has a first surface 101a and a second surface 101b disposed opposite to each other. Please refer to [reference needed]. Figure 4 .

[0062] In this embodiment, the first device board 101 is a quantum dot light-emitting layer.

[0063] In some embodiments, prior to the step of providing the first device board 101, the method may further include: sequentially forming and stacking an anode 107, a hole injection layer 106, and a hole transport layer 105, with the first device board 101 disposed on the side of the hole transport layer 105 away from the hole injection layer 106.

[0064] Step B2: Coat the first device board 101 with a metal oxide mixture.

[0065] In some embodiments, prior to step B2, the method further includes:

[0066] A doped metal oxide is formed by doping a first metal oxide with a metallic element, wherein the metallic element includes at least one of magnesium and aluminum, and the molar percentage of the metal to the first metal oxide is between 5% and 20%.

[0067] Specifically, by using elemental magnesium or aluminum to dope the first metal oxide, the conduction band of the first metal oxide is improved, so that the energy level of the conduction band of the quantum dot light-emitting layer and the doped metal oxide is matched, reducing the potential barrier between the doped metal oxide and the quantum dot light-emitting layer, which is beneficial to electron transport.

[0068] In some embodiments, the molar percentage of elemental magnesium or aluminum to the first metal oxide can be any one of 5%, 7%, 10%, 12%, 15%, 18%, or 20%. In this embodiment, the molar percentage of elemental magnesium or aluminum to the first metal oxide is between 5% and 20%. On the one hand, this ensures the doping ratio of elemental magnesium or aluminum, increases the conduction band bottom energy level of the metal oxide, and makes the quantum dot light-emitting layer and the conduction band bottom energy level of the doped metal oxide match. On the other hand, elemental magnesium or aluminum can form intrinsic hydroxyl ligands when dissolved in a solvent. The steric hindrance of the first metal oxide with hydroxyl ligands is small, and it is easy to aggregate and deposit under heating conditions. The aggregation temperature of the doped metal oxide is less than 60 degrees Celsius.

[0069] In some embodiments, the first metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO.

[0070] The second metal oxide is doped with ions selected from at least one of tin, selenium, or sulfur. When the ion is selected as cationic tin, the molar percentage of the ion to the second metal oxide is between 10% and 30%. Since the doping ability of tin ions to the second metal oxide is relatively weak, in this embodiment, the molar percentage of tin ions to the second metal oxide is between 10% and 30%. For example, the molar percentage of tin ions to the second metal oxide can be any one of 10%, 13%, 18%, 23%, 28%, or 30%. When the molar percentage of tin ions to the second metal oxide is between 10% and 30%, the conduction band bottom energy level of the formed ion-doped metal oxide is lowered, matching it with the conduction band bottom energy level of the cathode, which is beneficial for electron transport. When the ions are selected from anionic selenium or sulfur, the molar percentage of the ions to the second metal oxide is between 1% and 15%. Since selenium or sulfur ions have a strong doping ability with the second metal oxide, in this embodiment, the molar percentage of selenium or sulfur ions to the second metal oxide is between 1% and 15%. For example, the molar percentage of tin ions to the second metal oxide can be any one of 1%, 5%, 8%, 13%, and 15%. When the molar percentage of selenium or sulfur ions to the second metal oxide is between 1% and 15%, the conduction band bottom energy level of the formed ion-doped metal oxide is reduced, making it match the conduction band bottom energy level of the cathode, which is beneficial for electron transport.

[0071] Specifically, the second metal oxide is doped with at least one of tin ions, selenium ions, or sulfur ions to reduce the conduction band of the second metal oxide.

[0072] A ligand is added to the second metal oxide to form a coordination metal compound. The ligand is selected from thiols, alkanolamines, and polyhydroxy ethers. When the ligand is selected from thiols or alkanolamines, the molar percentage of the ligand to the second metal oxide is between 0.1% and 10%. When the ligand is selected from polyhydroxy ethers, the molar percentage of the ligand to the second metal oxide is between 10% and 50%.

[0073] In one embodiment, because the thiol or alkanolamine ligands have a strong coordination ability with the second metal oxide, the molar percentage of the thiol or alkanolamine to the second metal oxide is between 0.1% and 10%, for example, the molar percentage of the thiol or alkanolamine to the second metal oxide is any one of 0.1%, 1%, 3%, 5%, 8%, and 10%. The molar percentage of the thiol or alkanolamine to the second metal oxide between 0.1% and 10% effectively increases the steric hindrance of the second metal oxide, thereby enhancing the thermal stability of the coordinated metal oxide.

[0074] Similarly, since the coordination ability of polyhydroxy ether ligands to the second metal oxide is relatively weak, the molar percentage of polyhydroxy ether ligands to the second metal oxide is between 10% and 50%, for example, any one of 10%, 15%, 30%, 45%, or 50%. This molar percentage effectively increases the steric hindrance of the second metal oxide, thereby enhancing the thermal stability of the coordinated metal oxide.

[0075] In one embodiment, the second metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO.

[0076] Specifically, thiols, alkanolamines, or polyhydroxy ether ligands, such as ethanolamine, butanethiol, or tetraethylene glycol, are added to the second metal oxide to coordinate with it, forming a coordination metal compound. This increases the steric hindrance of the second metal oxide and improves its thermal stability. The coordination metal oxide has a heat resistance temperature greater than 60 degrees Celsius.

[0077] Doped metal oxides and coordinated metal compounds are dissolved in alcohols and / or ethers to form a metal oxide mixture, wherein the alcohols and ethers have boiling points greater than 80 degrees Celsius.

[0078] Step B3: At a first preset temperature, the metal oxide mixture is subjected to a first annealing treatment to form the first electron transport layer 102. Please refer to [reference needed]. Figure 5 .

[0079] Specifically, the metal oxide mixture is subjected to a first annealing treatment at a first preset temperature, causing the doped metal oxides to agglomerate on the first surface 101a, forming the first electron transport layer 102. The first preset temperature is higher than the thermal stability temperature of the doped metal oxides. In one embodiment, the first preset temperature is between 40 degrees Celsius and 70 degrees Celsius, and the annealing time is between 5 minutes and 40 minutes. When the metal oxide mixture is annealed at a temperature between 40 degrees Celsius and 70 degrees Celsius, the doped metal oxides with poor thermal stability preferentially agglomerate and deposit on the first surface 101a of the first device board 101, forming the first electron transport layer 102.

[0080] Step B4: At a second preset temperature, the metal oxide mixture undergoes a second annealing treatment to form a second electron transport layer 103. The second electron transport layer 103 is located on the side of the first electron transport layer 102 away from the first device board 101. The second preset temperature is higher than the first preset temperature. Please refer to [reference needed]. Figure 6 .

[0081] Specifically, at a second preset temperature, the metal oxide mixture undergoes a second annealing treatment, causing the coordination metal oxides or ion-doped coordination metal compounds to agglomerate on the side of the first electron transport layer 102 away from the first device plate 101, forming the second electron transport layer 103. In one embodiment, the second preset temperature is between 75 degrees Celsius and 130 degrees Celsius, and the annealing time is between 5 minutes and 70 minutes. When the metal oxide mixture is annealed at a temperature between 75 degrees Celsius and 130 degrees Celsius, the thermally stable coordination metal oxides or ion-doped coordination metal compounds in the metal oxide mixture agglomerate and deposit on the first electron transport layer 102, forming the second electron transport layer 103.

[0082] It should be understood that, in this embodiment, after the first annealing process, the heating device can continue to be heated, and then a second annealing process can be performed.

[0083] In one embodiment, annealing can be performed under negative pressure or normal pressure. The advantage of annealing under negative pressure is that the solvent evaporates more thoroughly, the first electron transport layer 102 and the second electron transport layer 103 formed by deposition are more uniform, and the stability of the first electron transport layer 102 and the second electron transport layer 103 is increased.

[0084] Step B5: Form a second device board 104 on the side of the second electron transport layer 103 away from the first electron transport layer 102. Please refer to [link to relevant documentation]. Figure 1 .

[0085] The second device board 104 is the cathode.

[0086] In the fabrication method of the light-emitting device provided in this application embodiment, a metal oxide mixture is coated onto the quantum dot light-emitting layer. Since the agglomeration temperatures of the doped metal oxides and coordinating metal compounds in the metal oxide mixture are different, a multi-stage annealing process can be used to anneal the metal oxide mixture. Thus, a first electron transport layer and a second electron transport layer are formed at different annealing temperatures. Compared with the prior art, the fabrication method of the light-emitting device in this embodiment solves the problem of cumbersome steps in fabricating the electron transport layer in light-emitting devices.

[0087] In addition, since the difference between the conduction band bottom energy level of the doped metal oxide and the quantum dot light-emitting layer is between 0.1 eV and 0.5 eV, the conduction band bottom energy level of the quantum dot light-emitting layer and the doped metal oxide is matched, reducing the potential barrier between the doped metal oxide and the quantum dot light-emitting layer; the difference between the conduction band bottom energy level of the coordination metal compound and the cathode is between 0.2 eV and 0.4 eV, reducing the potential barrier between the coordination metal compound and the cathode, which is conducive to the transfer of electrons from the cathode to the quantum dot light-emitting layer and improves the luminous efficiency of the light-emitting device.

[0088] Please refer to Figure 2 , Figure 3 , Figure 7 , Figure 8 and Figure 9 The method for manufacturing the light-emitting device 200 includes the following steps:

[0089] Step B1: Provide a first device board 201, the first device board 201 having a first surface 201a and a second surface 201b disposed opposite to each other.

[0090] In this embodiment, the first device board 201 is the cathode.

[0091] Step B2: Apply a metal oxide mixture to the first surface 201a.

[0092] In some embodiments, prior to step B2, the method further includes:

[0093] A doped coordination metal compound is formed by doping a first metal oxide with a metallic element and adding a ligand to the first metal oxide. The metallic element includes at least one of magnesium and aluminum. The molar percentage of the metallic element to the first metal oxide is between 5% and 20%. The ligand is selected from thiols, alkanolamines, and polyhydroxy ethers. When the ligand is selected from thiols or alkanolamines, the molar percentage of the ligand to the first metal oxide is between 0.1% and 10%. When the ligand is selected from polyhydroxy ethers, the molar percentage of the ligand to the first metal oxide is between 10% and 50%.

[0094] Specifically, by doping a first metal oxide with elemental magnesium or aluminum and adding ligands to the first metal oxide, the resulting doped metal compound coordinates with thiol, alkanolamine, or polyhydroxy ether ligands to form a doped coordination metal oxide. This improves the conduction band of the first metal oxide, allowing the quantum dot emitting layer and the doped coordination metal compound to match the band bottom energy level, reducing the potential barrier between the doped coordination metal compound and the quantum dot emitting layer, and facilitating electron transport.

[0095] In some embodiments, the molar percentage of magnesium or aluminum to the first metal oxide can be any one of 5%, 7%, 10%, 12%, 15%, 18%, or 20%. In this embodiment, the molar percentage of the elemental metal to the first metal oxide is between 5% and 20%, which ensures the doping ratio of the elemental metal, increases the conduction band bottom energy level of the metal oxide, and makes the conduction band bottom energy level of the quantum dot light-emitting layer and the doped coordination metal compound match.

[0096] In addition, by adding long-chain ligands to the doped metal oxide, the steric hindrance of the second metal oxide is increased, thereby improving the thermal stability of the first metal oxide. The heat resistance temperature of the doped coordination metal compound is greater than 60 degrees Celsius.

[0097] In some embodiments, the first metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO.

[0098] A second metal oxide is provided. In some embodiments, after the step of providing the second metal oxide, the method may further include: doping the second metal oxide with ions selected from at least one of tin, selenium, or sulfur, wherein when the ions are selected from cationic tin, the molar percentage of the ions to the second metal oxide is between 10% and 30%, and when the ions are selected from anionic selenium or sulfur, the molar percentage of the ions to the second metal oxide is between 1% and 15%.

[0099] Specifically, the second metal oxide is doped with at least one of tin ions, selenium ions, or sulfur ions to lower the conduction band of the second metal oxide, thereby matching the conduction band bottom energy level of the second metal oxide with that of the cathode.

[0100] In one embodiment, the second metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO.

[0101] Doped coordination metal compounds and second metal oxides or ion-doped metal oxides are dissolved in alcohol and / or ether solvents to form a metal oxide mixture.

[0102] Step B3: At a first preset temperature, the metal oxide mixture is subjected to a first annealing treatment to form a first electron transport layer 202, which is located on the first surface 101a.

[0103] Specifically, at a first preset temperature, the metal oxide mixture undergoes a first annealing treatment, causing the second metal oxide or ion-doped metal oxide to deposit on the first surface 201a, forming the first electron transport layer 202. The first preset temperature is higher than the thermal stability temperature of the second metal oxide or ion-doped metal oxide. In one embodiment, the first preset temperature is between 40 degrees Celsius and 70 degrees Celsius, and the annealing time is between 5 minutes and 40 minutes. When the metal oxide mixture is annealed at a temperature between 40 degrees Celsius and 70 degrees Celsius, the second metal oxide or ion-doped metal oxide with poor thermal stability preferentially agglomerates and deposits on the first surface 201a of the first device board 201, forming the first electron transport layer 202.

[0104] Step B4: At a second preset temperature, the metal oxide mixture is subjected to a second annealing treatment to form a second electron transport layer 203. The second electron transport layer 203 is located on the side of the first electron transport layer 202 away from the first device board 201. The second preset temperature is greater than the first preset temperature.

[0105] Specifically, at a second preset temperature, the metal oxide mixture undergoes a second annealing treatment, causing the doped coordination metal compounds to agglomerate on the side of the first electron transport layer 202 away from the first device plate 201, forming the second electron transport layer 203. In one embodiment, the second preset temperature is between 75 degrees Celsius and 130 degrees Celsius, and the annealing time is between 5 minutes and 70 minutes. When the metal oxide mixture is annealed at a temperature between 75 degrees Celsius and 130 degrees Celsius, the thermally stable doped coordination metal compounds in the metal oxide mixture agglomerate and deposit on the first electron transport layer 202, forming the second electron transport layer 203.

[0106] In one embodiment, annealing can be performed under negative pressure or at room temperature. The advantage of annealing under negative pressure is that the solvent evaporates more thoroughly, the first electron transport layer 202 and the second electron transport layer 203 formed by deposition are more uniform, and the stability of the first electron transport layer 202 and the second electron transport layer 203 is increased.

[0107] Step B5: A second device board 204 is formed on the side of the second electron transport layer 203 away from the first electron transport layer 202.

[0108] The second device board 204 is a quantum dot light-emitting layer.

[0109] In some embodiments, after step B5, the method may further include: sequentially forming a hole transport layer 205, a hole injection layer 206, and an anode 207 on the second device board 204.

[0110] In the method for fabricating a light-emitting device provided in this application embodiment, a metal oxide mixture is coated on a cathode. Since the aggregation temperatures of the doped coordination metal compounds and ion-doped metal oxides included in the metal oxide mixture are different, a multi-stage annealing process can be used to anneal the metal oxide mixture. Thus, a first electron transport layer and a second electron transport layer are formed at different annealing temperatures, solving the problem of cumbersome steps in fabricating the electron transport layer in the light-emitting device.

[0111] Furthermore, since the difference between the conduction band bottom energy level of the doped coordination metal compound and the quantum dot light-emitting layer is between 0.1 eV and 0.5 eV, the conduction band bottom energy level of the quantum dot light-emitting layer and the doped coordination metal compound is matched, reducing the potential barrier between the doped coordination metal compound and the quantum dot light-emitting layer; the difference between the conduction band bottom energy level of the ion-doped metal oxide or the second metal oxide and the cathode is between 0.2 eV and 0.4 eV, which reduces the potential barrier between the ion-doped metal oxide or the second metal oxide and the cathode, facilitating the transfer of electrons from the cathode to the quantum dot light-emitting layer and improving the luminous efficiency of the light-emitting device.

[0112] Please see Figure 10 This application also provides a display panel. The display panel 1000 includes an array substrate 300 and a light-emitting device 100 or a light-emitting device 200 disposed on the array substrate 300.

[0113] The light-emitting device 100 and the light-emitting device 200 are manufactured by the above-described method for manufacturing light-emitting devices.

[0114] This application provides a light-emitting device and its manufacturing method, as well as a display panel. In the manufacturing method of the light-emitting device provided in this application, a multi-stage annealing process is used to form an electron transport layer, which solves the problem of cumbersome manufacturing steps for the electron transport layer in the light-emitting device.

[0115] In summary, although the present application has disclosed the preferred embodiments as described above, the above preferred embodiments are not intended to limit the present application. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be determined by the scope defined in the claims.

Claims

1. A method for manufacturing a light-emitting device, characterized in that, Includes the following steps: Provide the first component board; A metal oxide mixture is coated on the first device board. The metal oxide mixture includes metal oxides and metal compounds. The thermal stability of the metal compounds is stronger than that of the metal oxides. At a first preset temperature, the metal oxide mixture is subjected to a first annealing treatment, and the metal oxides with poor thermal stability in the metal oxide mixture preferentially agglomerate and deposit onto the first device board to form a first electron transport layer. At a second preset temperature, the metal oxide mixture is subjected to a second annealing treatment, and the metal compounds with strong thermal stability in the metal oxide mixture agglomerate and deposit onto the first electron transport layer to form a second electron transport layer. The second electron transport layer is located on the side of the first electron transport layer away from the first device board, wherein the second preset temperature is greater than the first preset temperature. A second device board is formed on the side of the second electron transport layer that is away from the first electron transport layer; The first preset temperature is between 40 degrees Celsius and 70 degrees Celsius, and the second preset temperature is between 75 degrees Celsius and 130 degrees Celsius. The metal oxide includes doped metal oxides, and the metal compound includes coordinated metal oxides.

2. The method for manufacturing a light-emitting device according to claim 1, characterized in that, The metal compound includes doped coordinated metal oxides.

3. The method for manufacturing a light-emitting device according to claim 1, characterized in that, Before the step of coating the metal oxide mixture onto the first device board, the method further includes: A doped metal oxide is formed by doping a first metal oxide with a metallic element, wherein the metallic element includes at least one of magnesium and aluminum, and the molar percentage of the metallic element to the first metal oxide is between 5% and 20%. A ligand is added to a second metal oxide to form a coordination metal oxide. The ligand is selected from thiols, alkanolamines, and polyhydroxy ethers. When the ligand is selected from thiols or alkanolamines, the molar percentage of the ligand to the second metal oxide is between 0.1% and 10%. When the ligand is selected from polyhydroxy ethers, the molar percentage of the ligand to the second metal oxide is between 10% and 50%. The doped metal oxide and the coordinated metal oxide are dissolved in alcohol and / or ether solvents to form the metal oxide mixture.

4. The method for manufacturing a light-emitting device according to claim 3, characterized in that, Prior to the step of adding a ligand to the second metal oxide to form a coordination metal oxide, the method further includes: The second metal oxide is doped with ions selected from at least one of tin, selenium, or sulfur. When the ion is selected from cationic tin, the molar percentage of the ion to the second metal oxide is between 10% and 30%. When the ion is selected from anionic selenium or sulfur, the molar percentage of the ion to the second metal oxide is between 1% and 15%.

5. The method for manufacturing a light-emitting device according to claim 1, characterized in that, Before the step of coating the metal oxide mixture onto the first device board, the method further includes: A doped coordination metal oxide is formed by doping a first metal oxide with a metallic element and adding a ligand to the first metal oxide. The metallic element includes at least one of magnesium and aluminum. The molar percentage of the metallic element to the first metal oxide is between 5% and 20%. The ligand is selected from thiols, alkanolamines, and polyhydroxy ethers. When the ligand is selected from thiols or alkanolamines, the molar percentage of the ligand to the first metal oxide is between 0.1% and 10%. When the ligand is selected from polyhydroxy ethers, the molar percentage of the ligand to the first metal oxide is between 10% and 50%. Provide a second metal oxide; The doped coordinated metal oxide and the second metal oxide are dissolved in alcohol and / or ether solvents to form the metal oxide mixture.

6. The method for manufacturing a light-emitting device according to claim 5, characterized in that, Following the step of providing the second metal oxide, the method further includes: The second metal oxide is doped with ions to form an ion-doped metal oxide, wherein the ions are selected from at least one of tin, selenium, or sulfur. When the ions are selected from cationic tin, the molar percentage of the ions to the second metal oxide is between 10% and 30%. When the ions are selected from anionic selenium or sulfur, the molar percentage of the ions to the second metal oxide is between 1% and 15%.

7. The method for manufacturing a light-emitting device according to any one of claims 3 to 6, characterized in that, The first metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO, and the second metal oxide is selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO and InSnO.

8. The method for manufacturing a light-emitting device according to claim 1, characterized in that, The first device plate is a quantum dot light-emitting layer, and the second device plate is a cathode; or... The first device board is a cathode, and the second device board is a quantum dot light-emitting layer.

9. A light-emitting device, characterized in that, The light-emitting device is manufactured by the method of manufacturing the light-emitting device according to any one of claims 1 to 8.

10. A display panel, characterized in that, The display panel includes an array substrate and a light-emitting device as described in claim 9, wherein the light-emitting device is disposed on the array substrate.

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